Hand guard for rotary cutters



June 28, 1938. w NEALE E L 1 2,122,1U

HAND GUARD FOR ROTARY CUITER Filed March 22, 1957 2 Sheets-Sheet 1 June 2%, 1938.

5. w. NEALE ET AL HAND GUARD FOR ROTARY CUTTERS Filed March 22, 1957 2 Sheets-Sheet 2 Patented June 28, 1938 UNITED STATES PATE'E' 6PM Arthur Henry ham, England Handley, Northfield, Birming- Application March 22, 1937, Serial No. 132,420 In Great Britain April 8, 1936 3 Claims.

This invention has for its object to provide an improved automatic hand guard for use in combination with rotary cutters of the vertical spindle type for wood working and other analogous machines.

The invention comprises the combination of a rotary segmental guard adapted to be arranged concentrically with and to enclose a part of the rotary cutter, a movable abutment piece for af- .fording lateral support to the workpiece during the cutting operation, means whereby under lateral pressure applied to the abutment piece by the work piece the guard is caused to move to an unobstructive position relatively to the cutter, and means for automatically returning the guard to its protective position after release of the abutment piece.

In the accompanying sheets of explanatory drawingsz- Figures land 2 are plan views showing in two different positions respectively a hand guard constructed in accordance with the invention and applied to the rotary cutter of a wood Working machine.

Figure 3 is a sectional elevation on the line 3.3 of Figure 1.

Figures l and 5 are fragmentary views similar to Figures 1 and 2 but showing an alternative form of the movable part for supporting the work piece.

In applying the invention in the manner shown to a wood Working or other analogous machine of the kind in which over the bed a of the machine is arranged a cylindrical or other cutter b rotatable about a vertical axis, we employ a guard which can enclose the greater part of the periphery of the cutter. This guard is in the form of a substantially semi-cylindrical casing, and consists of a fixed part c, and a segmental rotary part 0! which can be moved about the axis of the cutter b for exposing or enclosing the portion of the cutter to which the work piece e is to be applied. Alternatively the guard can be adapted to enclose the whole of the periphery of the cutter, and the rotary part d can be arranged to open or close an aperture in'thefixed part c.

Adjacent to and extending at one end over the cutter b there is adjustably secured to the bed a). a stationary fence which at the cutter end is of circular form and carries the guard. Adjacent to the stationary fence 1 is arranged a movable fence 9 which is adapted to afford lateral support to the work piece during the cutting operation and which can be moved laterally with respect to the fixed fence and the cutter. The movable fence 0 is connected to the fixed fence fby a pair of parallel-motion links indicated by h, i, respectively, The upper end of the movable guard part (1 is secured to the lower end of a pivot pin 7' arranged coaxially with the cutter b and passing through the centre of the circular part of the To the upper end of the pivot pin a is secured a pinion k, and this is engaged by a rack Z secured to one end of a link m having its other end-pivotally attached to an extension n of the link 72.. The pivot pin 7 passes through slots 0 provided in flanged portions of the rack Z, and thus maintains the pinion k in constant engagement with the rack I but permits sliding movement of the latter.

The mechanism above described is arranged so that the movable fence 9 and the rotary guard part (1 are moved to their normal positions as, shown in Figure 1 by a spring 10 acting on the extension n of the link It as shown or'on any other convenient part of the mechanism. Al-

ternatively a weight may be used instead of the;

spring.

When the machine is not being used the rotary guard part (1 is in its operative position as' shown in Figure 1 in which it encloses the portion of the cutter adapted to act on the work piece c, but when the work piece is placed alongside the movable fence g and lateral pressure is applied by the operative to the movable fence through the work piece, the movable fence moves towards the fixed fence f and by this movement causes the rotary guard part d to turn about the axis of the cutter b from the position shown in Figure 1 into the position shown in Figure 2 in which the portion of the cutter for acting on the work piece is exposed. This turning movement of the guard part at is due to the movement of the links h m, and the consequential interaction of the rack Z and pinion k, accompanying the movement of the fence gtowards the fixed fence f. The work piece 6 can now be traversed over the cutter b, but should the work piece accidentally or intentionally be moved away from the movable fence 9 the latter returns to its initial position under the action of the spring 21, and thereby causes the segmental guard part d to swing to its original position over the previously exposed part of the cutter.

As shown a guide plate 1 encloses a part of the periphery of the cutter left exposed by the guard parts 0, d. The object of this guide plate is to direct shavings cut from the work piece to the opening contained between the adjacent ends of the guide plate and the fixed guard part 0.

For dealing with curved work pieces the connecting link i can be detached and the movable fence 9* substituted by another fence or abutment piece s of any suitable shape, as shown in Figures 4 and 5 according to which this abutment piece is made to a curved form and is arranged so that it moves with but is incapable of movement relatively to the link h. In the example shown the abutment piece s is attached at one end to the pivot spindle of the link h and at the other end to the link itself. Alternatively this abutment piece may be adapted for attachment to the outer end only of the link It.

By this invention we are able to effect the enclosing of rotary cutters and thereby safeguard the hands of operatives in a very simple and satisfactory manner, and with a minimum of interference with the freedom or convenience of the operatives.

The invention is not limited to the particular example above described as subordinate mechanical details may be varied to suit different requirements. Also the invention is not limited to wood working machines as it may be applied to machines employing rotary cutters for cutting metals or other materials.

Having thus described our invention what we claim as new and desire to secure by Letters Patent is:

1. A hand guard for rotary cutters of the vertical spindle type, comprising the combination of a rotary segmental guard adapted to be arranged concentrically with and to enclose a part of the rotary cutter, a movable abutment piece for guiding the work piece and for affording lateral support to the work piece during the cutting operation, means interconnecting the abutment piece and the guard whereby under lateral pressure applied to the abutment piece by the Work piece the guard is caused to move to an unobstructive position relatively to the cutter, and means for automatically returning the guard to its protective position after release of the abutment piece, substantially as described.

2. A hand guard for rotary cutters of the vertical spindle type, comprising the combination of a fixed guard part for enclosing a part of the cutter, a rotary segmental guard part adapted to be arranged concentrically with and to enclose the portion of the cutter to which the work piece is to be applied, a fixed fence, a movable fence for affording lateral support to the work piece during the cutting operation, parallel motion links interconnecting the movable and stationary fences, rack and pinion mechanism operatively connected with one of the links and adapted to move the rotary guard part into an unobstructive position relatively to the cutter upon lateral movement being imparted to the movable fence by the work piece, and means for automatically returning the rotary guard part to its protective position after release of the movable fence, substantially as described.

3. A hand guard for rotary cutters of the vertical spindle type, comprising the combination of a rotary segmental guard adapted to be arranged concentrically with and to enclose a part of the rotary cutter, a stationary fence, a movable abutment piece made to a curved form and serving to provide lateral support for a curved work piece during the cutting operation, means for pivotally interconnecting the abutment piece and the stationary fence, rack and pinion mechanism operatively connected to the segmental guard, means for interconnecting the rack and abutment piece so that the guard is moved by the said mechanism to an unobstructive position relatively to the cutter upon lateral pressure being applied to the abutment piece by the work piece, and means for automatically returning the guard to its protective position after release of the abutment piece, substantially as described.

EDGAR WALTER NEALE. ARTHUR HENRY HANDLEY. 

